I think the number of people who wants Apple to increase the size of the screen after 5 years is more than the number of people who wants it to remain at 3.5".
I totally agree with this comment. The iPhone portfolio consists of one phone with different degrees of performance -
boring. Apple have the perfect opportunity to introduce, in the same way as their MacBook line, a 'Pro' variant.
Having said that, even if they were to introduce a new iPhone line with a much bigger screen (>= GS3), larger battery (sacrifice thinness, which I literally couldn't care less about) and expandability ports (never happen, they'd rather please the media lobby than consumers) - there's still the problem of an aged operating system.
Apple have been sloppy in far too many areas. But as I commented at the start of the thread, their audience has changed. They'd rather introduce below-market upgrades and role in profit, than actually
invent.